隧道内双火源间竖向温度分布特征实验研究

Experimental study on vertical temperature distribution characteristics between double fire sources in tunnel

为探究自然通风隧道内双火源间区域的竖向温度分布特性,利用1:10小尺寸隧道模型开展了一系列隧道双火源火灾实验,重点探究了火源尺寸和火源间距对火源间区域的竖向温度分布的影响。结果表明,随着距离顶棚高度的增大,火源间竖向温度逐渐降低,并且距离顶棚高度达到一定值后火源间竖向温度开始趋于稳定;随着火源间距的增大,火源间区域受到的热辐射作用降低,因此火源间竖向温度会快速降低;McCaffrey模型能够较为精准地预测火焰完全合并以及火焰不完全合并时火焰合并点上部的竖向温度分布;通过量纲分析和实验数据拟合的方法建立了一个能够准确预测火焰不完全合并时火焰合并点下部的竖向温度分布分段表达式。

In order to explore the vertical temperature distribution characteristics in the region between double fire sources in a naturally ventilated tunnel,a series of tunnel fire experiments were conducted using a 1:10 scale tunnel model.The experiments focused on investigating the influence of fire source size and spacing on the vertical temperature distribution between the fire sources.The results show that with the increase of the distance from the ceiling height,the vertical temperature between the fire sources gradually decreases,and the vertical temperature between the fire sources begins to stabilize after the distance from the ceiling height reaches a certain value.With the increase of the distance between fire sources,the thermal radiation effect on the area between fire sources decreases,so the vertical temperature between fire sources decreases rapidly.The McCaffrey model can accurately predict the vertical temperature distribution at the upper part of the flame merging point when the flame is completely merged and when the flame is not completely merged.Through dimensional analysis and experimental data fitting,a piecewise expression of the vertical temperature distribution at the lower part of the flame merging point is established,which can accurately predict the vertical temperature distribution at the lower part of the flame merging point when the flame is not completely merged.